USB2 Isolator Prototypes Ready

There will be a hi-fi show in Penang 11-12 June 2022 which is only 3 weeks away. Luckily, with the completion of USB2 Isolator prototypes, we are ready to demonstrate AA Music Streamer with the isolator.

Just a few days before the weekend of Eid Mubarak festive holidays, the semi-assembled prototype PCBs (with 0402 capacitors assembled) arrived. We purchased only 4 units of Texas Instrument’s XISOUSB211 pre-production samples (limited to 2 pcs per order), hence at most only 4 prototype boards can be made. The hand-assembled boards were completed last week but the troubleshooting and testing were only completed this week.

Hand-soldering under Dino-Lite USB microscope

There were issues with TI’s footprint used in PCB design – the pitch was 0.66 mm (incorrect) when it’s supposed to be 0.65mm. It can be clearly seen from the above picture that not all pads were aligned correctly to the chip. With careful placement and soldering, there were no bridging. The PCIe brackets custom-made by Gompf Brackets Inc, USA were reused from the previous USB filter.

Assembled prototype board

Swiss-made Audio Consulting’s 24 AWG solid-core silver wire with cotton sleeving (for data lines) and USB2 4-way IDC connectors were used to connect motherboard’s internal USB2 header to the USB2 Isolator input (left side of above picture). A dedicated 5V isolated LPSU (with floating ground) feeds the peripheral side of the isolator. This 5V supply previously powers USB cards like JCAT USB XE and also the passive USB filter.

USB2 Isolator assembled inside FC10 case
Closer look at USB2 Isolator inside FC10 case

From the rear of Streacom FC10 case, the look is very similar to the previous USB filter. Connection to USB DAC is made through the PCIe bracket of USB2 Isolator, not motherboard’s USB2 ports.

FC10 rear view showing USB2 Isolator connection to USB DAC

I will not comment on how it sounds. Please come and visit our booth at Penang hi-fi show on 11-12 June at Ascott Hotel, Jalan Gurney, Penang. Formal announcement of the event is coming soon.

Please note that TI has not released the ISOUSB211 chip. The pre-production sample XISOUSB211 is no longer available for purchase. I hope it will be released to production soon so that we can start selling AA Music Streamer with the USB2 Isolator.

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By Anwar

Dr. Anwar Ali is a consultant in the area of Operations Research / Decision Science. During his free time and as a side business, he builds high-performance and moderate-cost music streamer.